Tagintersection design

I took this photo outside the café Memory Lane in Rotterdam because the man in the white shirt was standing in the “middle” of this intersection for a couple of minutes. Before he took this position, he was walking slowly across the intersection to the opposite corner as his car. He’s a livery driver, and he appeared to be waiting for his passenger.

This intersection is raised (the sidewalk is level with the road surface), and is uncontrolled (there are no traffic signals, stop signs, or yield signs). A bicyclist or motorist can pass through this intersection without having to stop unless someone is walking, or a bike or car is coming from their right.

This junction has no crosswalks, either. And no one honks. Especially not at the man who’s in the roadway.

Because he’s not in the roadway. He’s in a street, and streets are different. Streets are places for gathering, socializing, eating, connecting, traveling, and shopping. There was plenty of space for him to stand here, and for everyone else – including other motorists who were in their cars – to go about their business.

The multiple threats to bicyclists, to pedestrians, and to motorists, are pervasive in the depicted scene. There is low visibility for turning motorists which in turn causes them to encroach on the right of way of other street users, including other motorists, bicyclists, and pedestrians.

This single image shows everything that is inefficient and dangerous to bicyclists and motorists about the intersection between north-south Green Street and diagonal Milwaukee Avenue in River West. Motorists should be physically blocked from entering or exiting Green Street at this point because of the danger inherent in the current intersection design. The block of Green Street south of Milwaukee Avenue is so insignificant to the driving network that no other design intervention should be implemented.

The situation depicted in this photograph demonstrates why the City should implement filtered permeability and close this entrance of the Green Street/Milwaukee Avenue intersection to motor vehicle movement. While motorists would be barred from entering or exiting Green Street here bicyclists would still have access to Green Street as part of the low-stress bicycling network of which Green Street is a part, between Milwaukee and Van Buren Street in Greektown.

I first wrote about this problematic intersection in June on Streetsblog Chicago and it remains an issue. One of the two motor vehicles ahead is blocking part of the bike lane while the second threatens to enter it. The bus on the left prevents the bicyclist in the bike lane from maneuvering around either vehicle. The photo below shows the situation from a different angle, that of the motorist wanting to turn left.

The vehicle operator on the left – a bus driver, in this case – has stopped the vehicle because they can occupy the intersection with the vehicle, or leave it open. Essentially, the bus driver has stopped to “let” the motorists on Green Street proceed across Milwaukee and further north into Green Street or turn left onto Milwaukee. Their movements would, again, put the bicyclist in danger, and put themselves and other motorists in danger because they are making nearly-blind turns into faster moving traffic.

The threats to the motorist are as limitless as the ones to the bicyclist (although the bicyclist will experience much greater injury if the threat is realized). As the motorist is paying attention to other motor vehicle traffic the bicyclist is coming down this bike lane – yep, I took the photograph – and is additionally obscured by the line of parked cars on the bicyclist’s right, and is in the shadow of the bus and the buildings. It’s like there’s a perfect storm of blind spots.

The quickest way to implement a system of filtered permeability and raise the significance and safety of the Green Street and intersecting Milwaukee Avenue blocks within the low-stress bicycling network would be to install a series of large planter boxes that prevent motorists from entering or exiting Green Street but allow bicyclists to filter through the planters.

And skip any traffic impact study. Not a single parking space will be lost or be made inaccessible with the implementation. A traffic study is not an experiment, but has practically been a foreboding document that has only ever said “things will be different”. (A good plenty of them have also suggested adding multiple $300,000 traffic signals.)

“Instead of asking people to judge the unknown, the city’s leaders built something new and have proceded to let the public vet the idea once it’s already on the ground.”

Chicago maintains a Silver bike-friendly commenting ranking, yet my initial analysis shows that our metrics are below average among other Silver communities after which I’m led to believe we’re undeserving of the medal. Safety is a citizen’s number one concern when considering to use a bicycle for transportation and it will take an expansion of the low-stress bicycling network – currently not a priority – to deserve the current ranking or achieve anything higher.

This photograph depicts a nearly identical situation but from the perspective of the motorist on Green Street approaching Milwaukee Avenue. Two bicyclists have taken two routes around the motorist blocking the bike lane with their vehicle.

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There are many intersections in Chicago that are so long that, while cycling, I can enter it (by passing the stop bar) on a green light, be in it during the entire 3-second yellow phase, and exit the intersection after it’s been red for several seconds.

I don’t like this. I think it puts me at risk. We could make our intersections shorter or we could increase the length of the yellow and all-red phases. One of these intersections is Elston Avenue at Ashland Avenue. Going southbound on Elston Avenue, the distance from the west side to the east side is about 200 feet. Traveling at 14 MPH (because you didn’t have to stop, it was green when you arrived), that will take you 9.75 seconds to cross. Some people will be traveling faster but at this point you’re also riding uphill because of the railroad viaduct you just crossed under.

Traveling at 17 MPH, it will take you 8 seconds to cross – you’ll still be in the intersection when it’s red!

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And as we like to say in Chicago, Amsterdammers also said “it was no big deal”.

I love what you see happening in this photo. A person cycling across the intersection is looking back at a white van and a streetcar that seem like they’re going to collide. But no one will hit each other. The Netherlands has the lowest crash rate in the world.

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Update June 12, 2011: Added a link to and excerpt from commentary by David Hembrow, a British blogger in the Netherlands.

How does a 3-way street work? Easy, just watch the video.

I like the term “aggressive yield” to describe the situation when a motorist does yield to pedestrians crossing the street, but in a way where they inch forward continually, slowly pushing, with a buffer or air, the people out of the way.

those red markers are just showing the limits of tolerable risk as established by years of system development. If the collision speeds were higher, those red circles would be far few – it’s simply a system finding its own point of stability.

If you really want to wreak havoc – try to control that system without corrective feedback (eg more rules, lights, controls, etc) and you’ll see the system kill people while it tries to find new stable relationships.

don’t forget that rules, signs, lights, etc have no direct impact on the system – they only work through the interpretation of the users.

I don’t see the behaviour at this junction as being about “bad habits”. What I see is simply a very badly designed junction which almost invites people to behave in the way that they do.

Dutch road junctions don’t look like and work like this – they are different for a reason: it removes the conflicts and improves safety. A long-standing theme of Dutch road design is the concept of Sustainable Safety. The concept is to remove conflict so that collisions are rare and the consequences of those which remain are relatively small. Roads are made self-explanatory so that bad behaviour is reduced and the way people behave is changed.

Reading this reminds me of the work of the students in George Aye’s class at SAIC, “Living in a Smart City.” The students attempted, through an intersection redesign, to reduce the stresses that lead to crashes.

Where are the 3-way streets in your city? Grand/Halsted/Milwaukee in Chicago comes to my mind easily. Also a lot of streets in the Loop. Oh yeah, and The Crotch, at Milwaukee/North/Damen.

OLD: He didn’t mention the extents but I bet on the west end it will be at Milwaukee Avenue and Desplaines Street (see photos of this intersection below), where thousands of bicyclists per day come downtown from Milwaukee; on the east end it would be either Wells Street (a one-way, southbound street), which has a treated metal grate bridge and bike lane, or State Street (a two-way street), where the bridge is completely covered in concrete. To Wells Street is 0.53 miles, and to State Street is 0.84 miles, using the measurement tool on Google Maps.

NEW: The extent is from Milwaukee Avenue and Desplaines Street to Wells Street, a distance of 0.53 miles.

I’m excited that the Chicago Department of Transportation (CDOT) chose a good location, even though I don’t think this location meets either of my two criteria: that it attract new people to bicycling for everyday trips and that it reduce the number of crashes. It will do both, but only because that is intrinsic of this kind of infrastructure. The kind of bikeway will have more effect on this than the location. People who will use this protected bike lane are already cycling on Kinzie Street and there’re very few crashes here (there were 6 in 2007-2009).

So what makes Kinzie Street in River North a good location?

People will be riding and using it from Day 1. It’s a place where people are already riding. After a month, and after a year (heck, after three years), no one will be able to complain of its lack of use. For detractors, this is a main point used to advocate for bikeway removals.

There are low barriers to implementation: there’s a very supportive Alderman, the road is wide, and low automobile traffic (this is my observation; there’re no traffic counts recorded on the City’s website).

While I’m sure that CDOT planners and engineers have been working at a furious pace since May 16th to get this new bikeway designed and ready to install, I have a couple suggestions I hope they will consider slipping into the project plan to make it even better:

Intersection design

Problem 1: Improve the intersection at Milwaukee, Desplaines, and Kinzie. Going southbound on Milwaukee at this intersection, you are presented with two lanes. One that is “left turn only” and has a left turn signal, and one wide lane that is for “straight”. But there are three directions to go. One can turn right onto Desplaines, turn left onto Desplaines, or go straight with a slight left into Kinzie. In which lane do you position yourself and which signal do you follow? Actually, which signal to follow is easier because there’s a green right-turn light, and a regular through light. It’s really the lane and positioning that matters.

Possible Solution: This could be made more clear with a bike-only left turn lane (like this one at Milwaukee/Canal/Clinton) with a bike signal head (not sure if a bike-only phase in the signal cycle will be necessary).

Problem 2: Drivers in the right-most northbound lane on Desplaines may try to turn right into Kinzie and this will cause conflicting movements with bicyclists entering Kinzie from Milwaukee.

Possible Solution: Ban right turns on red at this corner (but probably all corners) and enforce the ban.

Slippery bridge

Problem: The bridge over the Chicago River has an open metal grate deck – these are very dangerous for bicycling, especially when wet.

Problem: The signed bike route signage is too late for bicyclists to base their turn decision on. The sign is at the intersection (see photo) and those who want to turn left towards Wells Street will then have to make a box turn instead of being able to make a left turn from the left turn lane.

Possible Solution: Install two signs, one before and one after the railroad viaduct which is north of this intersection along Milwaukee. The signs should say reach Wells Street via the Kinzie Cycle Track and position yourself in the left turn bike lane.

Bridge gap

Problem: The bridge seam on Desplaines at the south end of the intersection is extremely wide and deep. While not part of Kinzie, this problem could be fixed in the same project.

Possible Solution: Without reconstructing the bridge seam, I’m not aware of what can be done.

One more idea

Install a bike box at the intersection at westbound Kinzie at the top of the hill.

Where thousands of bicyclists will probably start their journey on the Kinzie Street protected bike lane.

I took this photo to try to demonstrate the confusion of where to position one’s self at the edge of the intersection if you want to travel “straight” into Kinzie Street (with a slight left). Do you put yourself in the left turn lane, or just to the right of the left turn lane?

The City of Chicago plans to make major changes to the intersection of Damen-Elston-Fullerton. They revealed a lot of these changes and invited the public to learn more and make comments on the current proposal at an open house event Wednesday, April 27, 2011, at the Wicker Park-Bucktown library.

What is now actually three, closely-spaced intersections with six legs (two of them skewed), will become three, distantly-spaced intersections at right angles.

Why is this being done?

The closely-spaced intersections “encourage poor decision making.”

Small radii makes it difficult for trucks to make turns.

The island and closely-spaced intersections makes for limited queue capacity which blocks the other legs.

There are a lot of crashes, over 400 in a 3-year period. That’s over 7 per week.

So what’s the solution?

The Chicago and Illinois Departments of Transportation, and project consultant Benesch came up with 4 alternatives.

Fullerton tunnel, or underpass. A majority of Fullerton traffic would bypass the intersection, but the surface intersection would still have same conditions outlined under “why.” Additionally, there are many utilities under the intersection that would all need to be relocated. It would take 3 years to build. For the length of the tunnel, surface traffic on Fullerton could only make right-in, right-out turns.

Overpass. A majority of Fullerton traffic would bypass the intersection, but the surface intersection would still have same dismal conditions. This has the same turn restrictions as the underpass – this and its imposing aesthetics could impact economic development (the presentation didn’t say whether the project designers expected this to be positive or negative).

And there’s the “preferred alternative.” It has wider sidewalks, larger turn radii, and “safer bike accommodations.” Delays would improve from up to 7 minutes to under 30 seconds.

Other benefits of the preferred alternative include:

Access to properties is preserved.

Simpler intersections means fewer conflicting movements.

A “new bike lane” (I disagree with calling it new – the project is preserving the existing bike lane, bringing it into the new route of Elston Avenue, or whatever the new street will be called).

2012 – While continuing work on the design, begin acquiring right of way.

2013 – Finish design, and bid out project.

2014 – Award project and begin construction.

The project is estimated to cost $32 million, with funds coming from the TIF Bank, grants from the FHWA, and the City’s own capital improvement funds.

Comment on the design until May 13 by emailing Bridget Stalla, the project manager who works for the City of Chicago. All emails to her about this project will go on the public record.

So what are my comments?

Lack of bike lanes

Currently there’s no striped bike lane for .26 miles on Damen Avenue between where it ends at the I-90/I-94 highway and railroad viaducts to where it ends on the hill to the bridge over the Chicago River.

The project does not add this bike lane, which I feel is much needed for the cyclists who deal with the congestion and tight spaces. I talked to Bridget and Colin Coad, a staffer at Benesch about this. Both admitted that a bike lane in this location was considered. It wasn’t in the current design because Damen Avenue must have two lanes northbound to keep the queue capacity and keep delays down. An animation showed the difference in delays between the existing and proposed intersection configuration. The delay reduction in the new configuration was very noticeable. This doesn’t preclude installing a bike lane.

An attendee asked Ryan Thady, who was explaining the animation, if Benesch had done analysis on a single northbound travel lane south of Fullerton Avenue on Damen Avenue. He answered, “No. If there’s one lane, there’s an increased delay.”

Colin said that a bike lane has always been under consideration and will be again under consideration. Bridget says she realizes there’s a need to reevaluate the bikes on Damen Avenue situation. “We need the two lanes to really make this thing work like it’s supposed to. We will look at extending the bike lane on Damen north of Fullerton [from the bridge approach to the intersection of Damen and Elston].”

I’m confused about “making this thing work like it’s supposed to.” After hearing this, I felt that I don’t know if it’s clear to me what this thing is supposed to do. I thought it was about improving safety and reducing delays. By having a bike lane, bicyclists’ safety will be improved and their delays will also be reduced.

Some bicyclists may be involved in collisions with motor vehicles here because they move against signals. The same is probably true for drivers who get into collisions: frustration and impatience and simply not knowing when you’ll have a turn may lead road users at this intersection to proceed when it’s not safe to do so (and against the signal). The project designers said that this intersection “encourages poor decision making.” With dedicated space, in the form of a bike lane, as well as simpler design and an expectation of when it will be one’s turn to go, bicyclists and drivers alike will better comply with intersection controls.

The plan does nothing to add bike lanes through the Elston or Damen intersections. The Damen bike lane currently ends 700 feet before the intersection. The Elston bike lane ends 400 feet before the intersection. That funny business needs to stop and we need bike lanes in Chicago that go THROUGH intersections, much like you see in New York City (example photo 1 and photo 2.

Complete Streets

My final comment, a quick one, is that the project made no mention of reduced travel times for those who ride the Fullerton or Damen Avenue buses through this intersection. We still have a long ways to go in accommodating, and caring about, our sustainable transportation modes.

Bicycle crashes are also not mentioned in the documentation, while motor vehicle crashes with pedestrians are. There were more crashes with bicyclists than with pedestrians in the 3-year period of 2007-2009 (12 versus 4). Bicycle counts have not yet been taken at this location; they should be conducted as soon as possible.

Complete Streets in Illinois needs to stop being a policy without any teeth and put into regular practice. Enough with just “considering” all transportation modes; we need to “provision” them.

Roundabout

Was a roundabout considered at this location? The Pennsylvania Department of Transportation’s Guide to Roundabouts (PDF) lists criteria on where to use roundabouts, including these which describe the intersections in question:

Large traffic signal delays

Heavy left turning traffic

More than four legs or unusual geometry

History of crashes involving crossing traffic

Traffic growth expected to be high and future traffic patterns uncertain or changeable [because Elston is a diagonal and near shopping, traffic volume will not change]

History of right angle crashes [this is true because of the confusing signal phases]

While three roundabouts may not be necessary, one should be considered at least for the Elston-Fullerton intersection, which has the most space available for such a facility.

Curve and wide road of New Elston Avenue

On “New Elston Avenue,” between Fullerton and Damen, there are two regular lanes and one bike lane in each direction. The widening of Elston was not justified. The high radius curve on New Elston Avenue on the east side of the project, and two regular lanes in each direction, will likely cause higher-speed traffic than bicyclists are used to on many roads on which they travel in great numbers. Automobile drivers speeding around the curve may enter the bike lanes. This is a good case for protected bike lanes at least on this part of the roadway. Thank you to A. Lottes for pointing out the curve to me.

Removing the Â center island

Some commenters on The Expired Meter have suggested removing the tinny center island (as well as removing the second stop bar and signal every road user passes over) and converting it to a simple six-way intersection like Lincoln-Ashland-Belmont. While doing so may reduce delays or the number of crashes, it would probably fail to do both. I think it should be a considered alternative.

Queue backups caused by Fullerton-highway ramp intersection

The plan does not address the westbound queue backups that start at the Fullerton intersection with the I-90/I-94 highway ramp. Westbound drivers constantly and consistently block the Fullerton intersections with Damen and Elston while waiting to go through the signal at the highway ramp. This intersection is outside the project area but pivotal in its success at reducing delays, at least with the “remaining,” new intersection at Damen.

View project overview (1 page PDF). Again, the project managers are saying there’s a new bike lane on Elston. It’s only new in the sense that it will be new thermoplastic on new pavement. It won’t be a new part of the bikeway network, just a moved part.

The end of the presentation said that all exhibit materials would be on the City’s website, but I didn’t find all the poster boards, so here are most of them in my Flickr photoset. I assume they would be posted here.

Photos

A visualization of the crash history (only automobiles and pedestrian types included) at the intersection.

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This screenshot from the Chicago Crash Browser map shows the location of bike-car collisions at Ogden/Milwaukee, an intersection that exemplifies the yellow trap problem the city hasn’t remedied.

List of the most crash-prone intersections on Milwaukee Avenue in Chicago. Using data from 2007-2009, when reported to the Chicago Police Department. Dooring data not included on the bike crash map. I used QGIS to draw a 50-feet buffer around the point where the intersection center lines meet.

Intersecting street (class 4*)

Bike crashes

Chicago Avenue (see Ogden below)

12 (17)

California Avenue

9

Halsted Street & Grand Avenue

7

Damen Avenue & North Avenue

6

Western Avenue

6

Ogden Avenue (see Chicago above)

5 (17)

Ashland Avenue

5

Diversey Avenue

5

Fullerton Avenue

5

Elston Avenue

5

Augusta Boulevard (not class 4)

5

Combine the six-way (with center triangle) intersection of Ogden, Milwaukee, Chicago, and you see 17 crashes. Add the 6 just outside the 50-feet buffer and you get 23 crashes. Compare this to the six-way (without center triangle) at Halsted, Milwaukee, Grand, where there’s only 7 crashes.

What about the two intersections causes such a difference in crashes? Let’s look at some data:

Traffic counts are assumed estimates. Counts are taken on a single day, either Tuesday, Wednesday, or Thursday. Bike counts at Halsted/Milwaukee/Grand were actually taken on Milwaukee several hundred feet northwest of the intersection so DO NOT include people biking on Halsted or Grand! This means that more than 3,100 people are biking through the intersection each day.

Intersection style tells us which kind of six-way intersection it is. At island styles you’ll find a concrete traffic island separating the three streets. You’ll also find three signal cycles because there are actually three intersections instead of one, making it a 12-way intersection. Also at these intersections you’ll see confusing instructional signage like, “OBEY YOUR SIGNAL ONLY” and “ONCOMING TRAFFIC HAS LONGER GREEN.”

These intersections are more likely to have a “yellow trap” – Ogden/Milwaukee definitely has this problem. The yellow trap occurs at that intersections when northbound, left-turning motorists (from Milwaukee to Ogden) get a red light but they still need to vacate the intersection. Thinking that oncoming traffic has a red light but are just being jerks and blowing the red light (when in fact they still have a green for 5-10 more seconds) they turn and sometimes hit the southbound traffic. The City of Chicago acknowledged this problem, for bicyclists especially, in summer 2013 but as of November 2014 the issue remains.

I can’t yet tell you how I obtained this data or created the map. I’m still working out the specifics in my procedures log. It involved some manual work at the end because in the resulting table that counted the number of crashes per intersection, every intersection was repeated, but the street names were in opposite columns.

Crash data from the Illinois Department of Transportation. Street data from the City of Chicago. Intersection data created with fTools in QGIS. To save time in this initial analysis, I only considered Milwaukee Avenue intersections with streets in the City of Chicago centerline file with a labeled CLASS of 1, 2, or 3.